hkovalcik

Deleted - think bad spark plug tubes are finally catching up and causing a bad vacuum leak at idle. Will replace and report back. Car wash prob just a coincidence.

allcool

Cracked coils getting wet. Once they dry will probably run fine.

jmo

hkovalcik

thanks allcool. just gonna buy coils/plugs/tubes and hope it fixes the issue. Had to've been the pressure washer, combined with the fact that I saw him start it and back it up a few feet, then turn it off again mid-wash. Not sure why he did that. Maybe he shorted something? Just hoping this isn't a bigger issue than it is. It's really running like sh*t at idle. No way new Beru coils went bad in just 30k miles.

yelcab

I rebuilt the engine in my neighbor's 996 and gave it back to him running well. His well-meaning young son washed and detailed the exterior. After, the neighbor brought the car back because it was misfiring. So, I asked him "Did you wash the car?" he said yes. We got in, drove the **** out of the car until the water soaked air filter dried out and it ran well again.

Lesson: never wash your Porsche 996/997 with a garden hose dousing water over the engine lid.

In your case, you should replace what ever ignition components that are older than 30,000 miles. AND never wash your car again. Use drywash.

hkovalcik

I wonder if water did get sucked up through the intake— doubt it though?? Or maybe it fouled the maf? I’m not getting any maf error codes and the car’s idle changes a bit when I disconnect it but doesn’t run better or worse. Air filter looked dry yesterday.

jayzbird

More likely a cracked coil as noted above unless he just went crazy filling the engine compartment with water. The no wash advice would seemingly imply never leave the car in the rain too. Clearly you can. I cover the motor with a towel washing, carefully avoiding the latch mechanism (in fact I just leave it unlatched), and of course removing before starting the car. More to prevent hard water spots everywhere than anything else.

hkovalcik

He definitely went crazy with the power washer, especially on the rear wheels and rear wheel wells. If you look at our cars, you can 100% spray water directly onto the coil connections on both banks. I watched him do it and he started the car mid-wash to back it up a few feet. I thought nothing of it. Probably cracked coils, just can't believe it given they're only ~30K miles old (so are the plugs). That makes me think something else is bad. I'm throwing a bunch of codes for misfires and the O2 sensors detecting a lean state, so the car's running rich. No misfiring through the powerband, only at idle. It does feel like it goes into some sort of limp mode from time to time, sometimes it actually feels pretty torquey - more than usual.

I have a cart loaded with FCP with new spark plug tubes, plugs and coils. I replaced the MAF 30k ago too. Only other possible culprit is the ICV so may just get another used one from DC Auto for peace of mind. Bad ICV wouldn't cause this poor of an idle though.... or would it? If it is just a $60 fix and I can replace the ICV, I'd much rather do that than unnecessarily swapping the coils and plugs. The wash/detail was also $220 so still struggling to pull trigger on parts that I wouldn't have had to replace otherwise lol. On my way there the thought of "I should just wash it myself" crossed my mind too. Car was running awesome before the wash and had no codes. Actually drove it from Philly to LA last March. Fun trip.

Thinking next steps are to pull the coils / inspect and re-seat the coil connections. I won't know if the MAF or O2's are actually bad unless I use a computer, so trying to get my hands on an Autel or someone with a Dura. I'm in Hermosa Beach, CA if anyone could lend a hand.......

GC996

FWIW, I have 62k on my 02 and over the past 21 years have replaced my coils 3x already. One will eventually show a misfire so I replace them all and the plugs. I have replaced my MAF once or twice as well. Eventually they go bad, crack, etc. Same can be said for fuel injectors. Just happens. High pressure water probably doesn't help.

allcool

Strange its still misfiring if its from water fouling cracked coils. Usually by the next day and a hot engine, they dry up and all is fine again. Unless a hot coil got a cold blast of water and cracked badly never to work right again.?

Well, if you know what cylinder(s) are misfiring, and have your old coil packs(and they're old but working), swap out the offending coil(s) and see if that changes things... Just a thought...

I wouldn't throw a bunch of parts at it, better to figure out whats wrong and fix it.

jmo

hkovalcik

Yeah believe me I don't want to start throwing parts / $ at it either. I already paid the $220 to get it washed haha....

Barely held an idle today and it's running very rich... idle goes up and down. could a power washer ruin the connectors to the coils themselves? Electrical problem now? Idk. Or water got sucked up and the MAF is toast? Doesn't run much different with MAF disconnected and don't think a bad maf would cause it to idle like sh*t unless I'm wrong.

allcool

Ya, wouldn't keep running it like that.
The imbalance could cause undo wear and tear on reciprocating parts.

Start with taking out the coil packs, do you still have the old ones..? do you know what cyl is misfiring, if so start there...? Is the air filter wet..?


Hmmm, idk, after rereading this thread, and it being more than enough time for things to dry out now if it was a water problem, maybe sideline the coils for now and do a simple check for vacuum leaks. I've seen aggressive pressure engine cleaning blow apart old vacuum lines, etc... Worth checking out first maybe,, if you can't get any codes to go by.

hkovalcik

Pulled a bunch of stuff tonight -
all bank 1 coils and plugs. The coils look brand new. The plugs look fine and are oil-free, even the one that I thought was leaking through the spark plug tube.

So now I'm thinking there's nothing wrong with the coils, plugs, or tubes.

I wonder if it is as simple as my ICV. I bought a used ICV from DC Auto ~30K ago (mileage unknown). I changed the MAF with a brand new Bosch unit ~30K ago as well. Might change those two first.

Only other thing I noticed is the TB was sort of dirty (but I highly doubt that would cause the stumbling (sometimes stalling...) idle), and the intake plenum had a bit of oil in it. If I looked inside bank 2's intake plenum, I could see a small pool of oil. I think that's normal though.

jumpy chunky

Sounds like your AOS is failing. Oil in the plenum is not normal.

Check with Porschetech 3 he will fix you up with the UAOS kit for your car.

Marv

The other possibility is a fractured or dislodged vacuum line.

Does the car throw codes?

jumpy chunky

When the AOS diaphragm ruptures that’s a big ‘ol’ vacuum leak as well.

I wouldn’t drive the car until AOS is inspected or replaced .